Systems and Methods for a Smoking Product Filter

ABSTRACT

A smoking product with one or more filters, such as a cigar or cigarette. The filters may comprise micro-fibers, nano-fibers, or a combination thereof, wherein the fibers are provided by electrospinning. The filters may be disc-shaped, hemispherical-shaped, convex lens-shaped, and/or may comprise one or more folding structures. The smoking product may be a tobacco product, and may comprise a plurality of filters comprising one or more materials and one or more sizes and/or shapes, and the filters may comprise fibers of provide a size gradient from a first end of the product to the second end. In addition, the filters may further comprise one or more catalysts adapted to adsorb or filter to reduce or remove one or more materials, which may be toxic. Methods of making the filters and tobacco products are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. provisionalpatent application Ser. No. 62/521,048, which was filed on June 16,2017, and which is hereby incorporated herein by reference.

BACKGROUND

The present disclosure relates to the field of smoking productfiltration, including cigar and cigarette filtration. In particular, itrelates to the addition of one or more layers of nano filters and/ormicro filters to the filter and the body of tobacco products, includingbut not limited to cigarettes and cigars, in the aim of effectivelyreducing the inhalation of toxic and hazardous substances and tar by thehuman body. Nano filters are composed of nanomaterials of which a singleunit is sized (in at least one dimension) between 1 and 1000 nanometers,including but not limited to nanofibrous materials, carbon nanotubes,carbon nanotube membranes, and graphene oxide. Micro filters arecomposed of micromaterials of which a single unit is sized (in at leastone dimension) between 1 and 1000 micrometers, including but not limitedto meltblown nonwoven fabrics, carbon fibers, carbon fiber cloths,carbon membranes, and carbon fiber membranes. Nanomaterials andmicromaterials can be interwoven or synthesized together to form afilter with mixed sizes of constituent elements. The present disclosurealso relates to a method for preparing nanofibrous layers usingelectrospinning.

In order to minimize the impacts of smoking on human health, to protectthe health of people living around the smokers and in the environmentaffected by smoking, and to prevent the intake of respirable particulatematters and other harmful and unhealthy substances from smoking intohuman body, there is increasing attention on adding filter layers tocigarettes. A variety of filtering methods and filter materials havebeen studied for cigarette filtration. However, conventional researchand the application of filter materials to reduce the inhalation ofparticulate matter have not fully met the filtration requirements on theparticles and harmful substances generated during cigarette smoking.

In the last century, cigarette filters have widely been used to reducethe harmfulness of smoking on human health. In the 1930s, doctors andresearchers published a series of studies on the relation betweensmoking and lung diseases. At that time, cigarette filters began toreceive attention. The purpose of a filter in a cigarette is to reducethe amount of tar and suspended particles in smoke inhaled by a smokerfrom burning tobacco. There is a dilemma: in order to block tar andsmall-sized particles, the filter has to be less porous, with highfiltration efficiency, but unfortunately as a result, the filter easilybecomes clogged by tar and toxic articles. If a filter is clogged, it isimpossible for smokers to smoke after only a few puffs. There is anurgent need to find a solution such that fine particles can be blockedwhile smokers do not suffer from clogged filters.

Electrospinning is a technique that uses a polymer solution or a melt toform a jet stream under a strong electric field for spinning. In recentyears, due to its ultra-fine fiber processing technology,electrospinning has received more and more attention. There arecurrently at least 30 kinds of polymers that can be electrospun,including natural polymers such as DNA, collagen, and silk protein, andsynthetic polymers including polyoxyethylene, polyacrylonitrile, nylon,polyvinyl alcohol, polyurethane, and polyester. Compared to othermethods that are expensive, time-consuming, and easy to cause pollution,electrospinning can save a lot of cost and energy.

In order to enhance the filtration of tar, nicotine, and suspendedparticles, various materials and structures for a cigarette filter havebeen proposed. PCT application WO 2004/080217 A1 discloses a method ofelectrically processed phenolic materials and the application of suchmaterials to cigarettes. The method of electrical processing in WO2004/080217 A1 is essentially the same as the electrospinning method,but the method also includes steps of drying and high-temperaturecarbonization after electrical processing. The method can be used for toproduce nano/micro fibers and particles. Such anodized phenolicmaterials used in cigarettes are not safe. Also, carbonated phenolicmaterials are brittle and easy to be inhaled. When fine micro/nanofibers or particles are used as filler materials in the filter andplaced in the filter with a small pore size, the filter layer is easilyclogged with tar or particles of harmful substances.

PCT application WO 2007/048359 A1 discloses the design of mixing 5 to 10percent nanofibers into a micron fiber filter. With the introduction ofnanofibers, it increases the surface area of the material and hence itsfiltration capacity. The disclosure in WO 2007/048359 A1 still usesconventional acetate fibers as filter materials. This disclosureprovides a small improvement on filtration effects because the amount ofnanofibers is low. At the same time, due to the mixed design of usingnano and micron fibers, the tar, nicotine, suspended particles are morelikely to pass through the micron fibers. The nanofibers do not functionwell, as when fine micro/nano fibers or particles with small pore sizesare placed in the filter as filter materials, the filter layer is easilyclogged with tar or particles of harmful substances.

PCT application WO 2013/164623 A1 discloses the addition of short fiberswith adsorbents or adsorbed particles on the surface of the cigarettefilters. The diameter and length of the short fibers are approximately5-9 millimeters and 5-20 millimeters, respectively. Short fibers are amixture of acetate fibers and other common polymer fibers. The size ofthe adsorbents or adsorbed particles, including activated carbon, on thefibers is between 0.1 and 1 millimeters. The materials used in theinvention do not reach the nanoscale either in the diameter of the fiberor in the particle size. The materials are not safe.

Chinese patent CN 102423141 A discloses a method for using anelectrospun acetate fiber membrane in the cigarette filter to improvethe efficiency of harmful substances filtration. The solvents used areacetone and dimethyl acetamide. Solvent residues are likely contained inthe electrospun membrane if the solvent evaporation is not wellcompleted during the production process, leading to potential healthrisks to smokers. The patent puts the fiber membrane inside thecigarette filter tip portion. Filtration effects and respiratoryresistances cannot be well controlled.

Chinese Patent CN 103625090 A discloses a method to prepare a nanofibermembrane modified paper substrate by electrospinning and itsapplication. The nano-spun yarns are between 500 nm and 1 μm indiameter, with a narrow spinning range and larger diameter than theeffective nanomaterial filtration.

Because of their excellent filtration effects, electrospinning materialshave been developed as filter materials, such as masks, to improve humanrespiratory health. Chinese Patent CN 104740934 A discloses astereoscopic electrospinning filter material for a mask and apreparation method thereof. The invention uses polyvinyl butyral as asubstrate, and a micro/nanofiber film of 0.2 microns to 1.5 microns insize is prepared on a stereoscopic model using an electrospinningtechnique. The solvent used in CN 104740934 A is ethanol, which is notas safe and reliable as using a water solvent to produce nano fibers forlarge-scale production. The diameters of micro/nano fibers prepared inthe disclosure in CN 104740934 A are in the range of 0.2 to 1.5 microns,a range that is too small, and the control of the product is not asgood. The spinning solution concentration of the polymer polyvinylbutyral is 0.06 g/ml, which is too low.

Chinese Patent CN 102872654 A and CN 102920067 A disclose the use ofelectrospinning to produce a mask capable of filtering pollutants of 2.5microns in size or larger. However, the polymer used and the solventsused for preparing the electrospinning solution are toxic, posingserious health risks if a complete evaporation of solvent cannot beachieved. At the same time, the filter materials prepared by thesepatents are not as effective for filtration of pollutants of 2.5 micronsin size or larger.

SUMMARY

A first advantage of the present disclosure relates to the placement ofone or more filters in a body of a tobacco product or other body forsmoking to filter harmful substances caused by smoking therebyprotecting human health. The advantage of adding filters to thecigarette body is that the filters can be burnt up, before they areclogged by the accumulation of tar and particles, along with the tobaccoin the cigarette body.

A second advantage of the present disclosure is that the surface area ofthe filter(s) can be increased when specific shapes of the filters areadopted, thereby allowing the same sized filter to tolerate a higheramount of tar without clogging.

A third advantage of the present disclosure is that when multiple filterlayers are deployed within one filter, their porosities and thicknessescan vary and they can be placed in either the cigarette filter and/orbody section, e.g., filter layers with larger porosities can be closerto the lit end of the cigarette to capture larger contaminants andfilter layers with smaller porosity can be closer to the mouth of thesmoker to capture smaller contaminants. The porosity determines thesizes of the contaminants that a filter layer can capture, with lessporous filters being able to block smaller particles. As a result, finerfilter layers, or filter layers that are less porous will unlikely beclogged by larger contaminants, hence enhancing their capability toblock more finer contaminants. Similar results can be achieved whenmultiple filters—but with different porosities—are placed in either thecigarette filter and/or body section.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood with regard to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1A is a perspective view of a cigarette containing a filter in itsfilter tip portion, which is cone-shaped according to a first embodimentof the present disclosure.

FIG. 1B is a perspective view of a cigarette containing a filter in itsbody section, which is cone-shaped according to a first embodiment ofthe present disclosure.

FIG. 1C is a perspective view of a cigarette containing a filter in itsfilter tip portion and another filter in its body section, both of whichare cone-shaped according to a first embodiment of the presentdisclosure.

FIG. 1D is a cross-sectional view of a cone-shaped filter in FIGS. 1A,1B, and 1C according to a first embodiment of the present disclosure.

FIG. 1E is a cross-sectional view of a cone-shaped filter in FIGS. 1A,1B, and 1C according to a first embodiment of the present disclosure.

FIG. 2A is a perspective view of a cigarette containing three filters inits filter tip portion, which are hemisphere-shaped according to asecond embodiment of the present disclosure.

FIG. 2B is a perspective view of a cigarette containing three filters inits body section, which are hemisphere-shaped according to a secondembodiment of the present disclosure.

FIG. 2C is a perspective view of a cigarette containing one filter inits filter tip portion and two filters in its body section, all of whichare hemisphere-shaped according to a second embodiment of the presentdisclosure.

FIG. 2D is a cross-sectional view of a hemisphere-shaped filter in FIGS.2A, 2B, and 2C according to a second embodiment of the presentdisclosure.

FIG. 2E is a cross-sectional view of a hemisphere-shaped filter in FIGS.2A, 2B, and 2C according to a second embodiment of the presentdisclosure.

FIG. 3A is a perspective view of a cigarette containing three filters inits filter tip portion, which have a folding structure according to athird embodiment of the present disclosure.

FIG. 3B is a perspective view of a cigarette containing three filters inits body section, which have a folding structure according to a thirdembodiment of the present disclosure.

FIG. 3C is a perspective view of a cigarette containing two filters inits filter tip portion and two filter in its body section, all of whichhave a folding structure according to a third embodiment of the presentdisclosure.

FIG. 3D is a cross-sectional view of a filter in FIGS. 3A, 3B, and 3C,which has a folding structure according to a third embodiment of thepresent disclosure.

FIG. 3E is a cross-sectional view of a filter in FIGS. 3A, 3B, and 3C,which has a folding structure according to a third embodiment of thepresent disclosure.

FIG. 4 is a perspective view of a cigarette containing a filter that isdisc shaped and with different layers according to a fourth embodimentof the present disclosure.

FIG. 5A is a perspective view of a cigarette containing three filters inthe body portion of the cigarette, with an unevenly distributedplacement in the cigarette body.

FIG. 5B is a perspective view of a cigarette containing three filters inthe body portion of the cigarette, with an evenly distributed placementin the cigarette body.

DETAILED DESCRIPTION

The present disclosure can be better understood by the followingdiscussion of the manufacture and use of certain preferred embodiments.Like reference numerals are used to describe like parts in all figuresof the drawings.

This present disclosure applies one or more filters in tobacco productsincluding but not limited to cigarettes and cigars, especially for thefiltration of toxic suspended particles, with each filter capable ofcontaining one of more layers. Both the layers and filters can displaydifferent porosities. Preferably, the filters have a large surface area.Using nano-sized and/or micro-sized particle filtration, the filters caneffectively reduce tar and other harmful impurities in smoke, oraerosol, and reduce irritation to the respiratory tracts to protecthuman health. Filters in the present disclosure can be made ofbiodegradable materials. Preferably, the selected materials are nottoxic and have no side effects. Nanofibers produced by electrospinningcan be used in the filters due to their cost effectiveness.

In the present disclosure, the concept of filtration includes any or acombination of various mechanical, physical, chemical, or biologicaloperations or materials that blocks, restricts, adsorbs, traps,disintegrates, destroys, damages, or has any means of restrictingcertain substances from passing from one point to another, or filter.The substances filtered can be in solid, liquid or gas format.

During the combustion of tobacco leaves, a plurality of harmful gaseouscomponents may be generated, including but not limited to at least oneof carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde,acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine,nitrosamine, nitrogen oxide, benzene, n-nitrosonornicotine (NNN),phenol, catechol, benzoanthracene, and benzopyrene. A large number ofstudies have been carried out on reducing harmful gaseous componentsfrom burning tobacco, such as applying filter tips. Such filter tips areoften clogged or filled with tar after only a few puffs. According tothe present disclosure, the filter(s) is directly placed in thecigarette body, and the filter(s) has a specific adsorption effectand/or is mixed with a specific catalyst, so that more harmful materialscan be removed when the filter(s) is designed to possess a large surfacearea. Particularly, the filter(s) can be burnt out along with thecombustion of the tobacco in the cigarette body. Harmful chemicals canbe subject to thermal decomposition and/or catalytic decomposition underthe high temperature of combustion, and thus reducing inhalation ofharmful gas by human body.

When cigarettes are burned, aerosol and tar are produced. After coolingdown, tar is in oily liquid form, containing a large number of harmfulsubstances. It's important to filter and remove selectively the harmfulsubstances, and reduce tar. As nicotine and flavor chemicals are also inthe aerosol and tar, care needs to be taken to preserve flavors. Generaltar filtration methods using acetate fibers only are problematic becausethe filters quickly become clogged. In cases when fine or ultrafinefibers are employed to remove small aerosol particles, smokers oftencannot even smoke after a few puffs.

The present disclosure employs two approaches to avoid the cloggingproblem.

First, one or more filters can be placed in a body of a tobacco product.In case there is more than one filter, the number of filters per unitdistance can be set to increase gradually towards the filter tip portion(non-lit end) of the cigarette. Tar clogging can be avoided as thefilter or filters close to the lit end are burned subsequently duringsmoking. That is, as more and more tar accumulates on the filter closerto the lit end, that filter is to be burned when smoking continues,thereby destroying the clogged filter. In another variation of thecurrent design where multiple filters are employed, the number offilters per unit distance remains the same, but the thickness of eachlayer is gradually increased toward the end of the cigarette, which canalso prevent the clogging of the tar while maintaining a high filtrationefficiency.

Secondly, multiple layers with different porosities can be boundtogether to form a filter, called a multi-layer filter, to alleviate theclogging problem. A multi-layer filter effectively enlarges the surfacearea for filtration. In the present disclosure, one or more multi-layerfilters are placed in either the cigarette body, or the tobacco section,or both. The layer(s) that is more porous or that can block only coarseor large particles can be located closer to the lit end of thecigarette, while the layer(s) that is less porous or that can blockfiner particles can be located closer to filter tip portion of thecigarette. With such an arrangement, larger particles will be blocked orabsorbed by the layer(s) closer to the lit end. They will not clog thelayer that is designed to block finer particles.

FIG. 1A is a perspective view of a cigarette 100 containing a filter 130according to a first embodiment of the present disclosure. In the firstembodiment, a filter having a substantially conical shape is embeddedwithin the filter tip portion of the cigarette. A cigarette 100comprises a body portion 110, tobacco 112(which may be tobacco leaves)rolled into the body portion 110), a filter tip portion 120, acetatefibers 122 that are within the filter tip portion 120, and a filter 130that is substantially cone shaped and embedded within the acetate fiber122 of the filter tip portion 120. A single filter 130 or multiplefilters 130 can be placed within the acetate fiber 122 of the filter tipportion 120 depending on specific filtration requirements.

FIG. 1B is a perspective view of a cigarette 100 containing the samefilter 130 as that in FIG. 1A, which is placed in the body, or tobacco,portion of the cigarette. This filter can be burned during smoking, thusavoiding being clogged by tars and other contaminants.

FIG. 1C is a perspective view of a cigarette 100 containing two filters130 that are the same as that in FIG. 1A, which are placed in the filterand the body portions of the cigarette, respectively. The filter in thecigarette body can be burned during smoking, thus avoiding being cloggedby tars and other contaminants.

Referring now to FIG. 1D, there are at least two layers in at least onefilter, with the first layer closer to the lit end of the cigarette andthe second layer closer to the filter tip portion of the cigarette.Multiple layers with different porosities or filtration capabilities canbe placed or bound together to form a filter, called a multi-layerfilter, in which the first layer is designed to block or adsorb ordisintegrate particles with larger sizes than the second layer. Forexample, the filter 130 comprises of a spunlace nonwovens layer 132 anda nanofiber membrane layer 134. Bound together, these two layers form acone-shaped two-layer filter. The spunlace layer 132 can be made offibers with larger diameters, for example, from 2 to 20 millimeters. Thenanofiber membrane layer 134 can be made from fibers with diameters from10 to 500 nanometers. Unlike the nanofiber membrane layer 134, layer 132is unable to block ultra-fine particles, but only larger, coarsergranules. Hence layer 134 is shielded from and unlikely to be clogged bylarger particles. The filter 130 can be made of materials that arenon-toxic and harmless. Referring now to FIG. 1E, alternatively thefilter 130 can comprise of a meltblown nonwoven fabrics layer 136 and ananofiber membrane layer 134. The diameters of fibers or nanotubes thatconstitute filter 130 can be between 1 nanometers and 5 microns, whichcan effectively filter out toxic substances, harmful substances andsolid particles produced by the combustion of the tobacco 112 of thecigarette 100. The filter 130 can be configured to reduce one or more ofthe gaseous components in the smoke through, for example, specificadsorption materials and/or specific catalysts that can decompose of atleast one harmful gaseous component. The cone shape of the filter 130can filter tar to a large extent by allowing tar deposits to form at thetip of the conical structure, serving both a filtration and a storagefunction, while air and smoke can still flow through the walls of thecone shaped filters.

FIG. 2A is a perspective view of a cigarette 200 containing threefilters 140 according to a second embodiment of the present disclosure.In the second embodiment, three filters with a substantiallyhemispherical shape are embedded within the filter tip portion of thecigarette. The cigarette 200 comprises a body portion 110, tobacco 112,a filter tip portion 120, acetate fibers 122 that are within the filtertip portion 120, and three filters 140 that are substantiallyhemispherical shaped embedded within the acetate fiber 122 of the filtertip portion 120. If necessary, one single filter 140, instead ofmultiple ones, can be placed within the acetate fiber 122 of the filtertip portion 120.

FIG. 2B is a perspective view of a cigarette 200 containing threefilters 140 that may be the same as those in FIG. 2A, but are placed inthe body portion of the cigarette 200. These filters can be burnedduring smoking, to avoid being clogged by tars and other contaminants.If necessary, one single filter, instead of multiple filters, can beplaced within the cigarette body 110 depending on specific filtrationrequirements.

FIG. 2C is a perspective view of a cigarette 200 containing threefilters 140 that may be the same as those in FIG. 2A, but one is placedin the filter tip portion and the other two are placed in the bodyportion of the cigarette 200. The filters in the cigarette body can beburned during smoking, to avoid being clogged by tars and othercontaminants.

Referring now to FIG. 2D, which is a cross-sectional view of the filter140, the generally hemisphere-shaped filter 140 shown comprises aspunlace nonwovens layer 142 and a nanofiber membrane or a nanotubemembrane layer 144. The spunlace layer 142 forms the inner layer of thehemisphere-shaped filter 140 while the nanofiber membrane layer 144forms the outer layer of the hemisphere-shaped filter 140. The spunlacelayer 142 may be made of fibers with larger diameters. Unlike thenanofiber membrane layer 144, layer 142 is unable to block ultra-fineparticles, but only larger, coarser granules. Hence layer 144 isunlikely to be clogged by larger particles. The filters 140 can be madeof non-toxic and harmless materials. Referring now to FIG. 2E,alternatively the filter 140 can be comprised of a meltblown nonwovenfabrics layer 146 and a nanofiber membrane layer 144. The diameter offibers or nanotubes that constitute the filter 140 may be between 1nanometers and 5 microns, which can effectively filter out toxicsubstances, harmful substances and solid particles produced by thecombustion of the tobacco leaves 112 of the cigarette 200. The filter140 can be configured to reduce one or more of the gaseous components inthe smoke through, for example, specific adsorption materials and/orspecific catalysts that can decompose of at least one harmful gaseouscomponent.

FIG. 3A is a perspective view of a cigarette 300 containing two filters,151 and 152, according to a third embodiment of the present disclosure.In the third embodiment, two filters with a folded structure areembedded within the filter tip portion of the cigarette. A cigarette 300comprises a body portion 110, tobacco 112, a filter tip portion 120,acetate fibers 122 that are within the filter tip portion 120, and twofilters 151 and 152 that comprise a folded structure embedded within theacetate fibers 122 of the filter tip portion 120. Alternatively, thefilters in the filter tip portion 122 can be either of the same type ordifferent types. If necessary, one single filter, instead of multiplefilters, can be placed within the acetate fibers 122 of the filter tipportion 120 depending on specific filtration requirements.

FIG. 3B is a perspective view of a cigarette 300 containing threefilters 150 that may be the same as those in FIG. 3A, but are placed inthe body portion of the cigarette 300. These filters can be burnedduring smoking, to avoid being clogged by tars and other contaminants.

FIG. 3C is a perspective view of a cigarette 300 containing four filters150 that may be the same as those in FIG. 3A, but two are placed in thefilter tip portion and the other two are placed in the body portion ofthe cigarette 300. The filters in the cigarette body can be burnedduring smoking, to avoid being clogged by tars and other contaminants.

Referring now to FIGS. 3D and 3E, different filters have differentfiltration or adsorption capabilities, for example, the filter 151 maybe made of either spunlace nonwovens or meltblown nonwoven fabrics orany other materials and structures such that filter 151 can capturelarger, coarser particles. The filter 152 is made of nanofiber membranesor nanotube membranes or other materials and structures such that filter152 is designed to block finer or ultrafine particles. With such anarrangement, filter 152 is unlikely to be clogged by larger particles.Both filters 151 and 152 can be made of non-toxic and harmlessmaterials. The diameter of fibers or nanotubes that constitute thefilters 151 and 152 is between 1 nanometers and 5 microns, which caneffectively filter out toxic substances, harmful substances and solidparticles produced by the combustion of the tobacco 112 of the cigarette100.

FIG. 4 is a perspective view of a cigarette 400 containing multiplefilters according to a fourth embodiment of the present disclosure. Inthe fourth embodiment, at least one filter having a substantially discshape is embedded within the body portion of the cigarette and/or thefilter tip portion of the cigarette. A cigarette 400 comprises a bodyportion 110, tobacco leaves 112 rolled into the body portion 110, afilter tip portion 120, acetate fibers 122 within the filter tip portion120, and a filter 160 that is disc shaped embedded within the acetatefibers 122 of the filter tip portion 120. A second filter 170 that isdisc shaped is placed within the body portion 110 of the cigarette 400.

The filter 160 can comprise of one or a combination of a nanofiber layeror a micro meltblown nonwoven layer, and/or other layers with differentporosities. In the exemplary embodiment of FIG. 4, a first filter 160 isplaced in the filter tip portion 120 and comprises of a layer 166 madeof porous nonwoven fabrics, a micro meltblown nonwoven fabrics layer164, and a nanofiber layer 162. A second filter 170 is placed in thebody portion 110 and comprises of a micro meltblown nonwoven fabricslayer 174 and a nanofiber layer 172. The filter 170 in the cigarettebody can be burned without affecting the combustion of the cigarette.The micro/nano filter layer is composed of nanofibers and micron fibersprepared by electrospinning and meltblown. The burning of the filterwill result with non-toxic and harmless substances. The diameters of thefibers can be between 100 nanometer and 5 microns. The filter 170 can beconfigured to reduce one or more of the gaseous components in the smokethrough, for example, specific adsorption materials and/or specificcatalysts that can decompose of at least one harmful gaseous component.

FIG. 5A is a perspective view of a cigarette containing three filters ina body portion of the cigarette, with an unevenly distributed placementin the cigarette body. Filtering of the tar produced by cigaretteburning is one of the most important ways to reduce the harmfulsubstances inhaled by the human body. The general method of tarfiltration using a single filter tip portion with acetate fibersattached to the end furthest from the lit-end of the cigarette tends tocause the tar to clog the filter, affecting further filtration. Asdescribed above, the present disclosure adds single-layer or multi-layermicro/nano filters in the cigarette body portion and/or the filter tipportion. Referring now to FIG. 5A, three filters 160 a, 160 b, and 160 care placed within the cigarette 400. When the cigarette is burning, thefilter 160 a closest to the lit end will be the first filter to filterthe tar. It will be burned before it becomes clogged with tar. Thefilters 160 b and 160 c will continue to filter tar and contaminants.Filters 160 a and 160 b can be placed closer to the lit end of thecigarette because the first few initial puffs on the cigarette by asmoker are often the heaviest puffs. This arrangement allows for greaterfiltration when the smoker first starts to smoke the cigarette.Referring now to FIG. 5B, three filters 160 a, 160 b, and 160 c areplaced within the body portion 110 of the cigarette 400. The threefilters can be placed so that the amount of tobacco 112 between them isevenly distributed.

Although the filters in FIGS. 5A and 5B are disc shaped in this example,the filters can be cone shaped, hemisphere shaped, with a foldingstructure as described above, or of some other shapes and structures asneeded. The thickness or filtration capabilities of each filter can alsobe adjusted.

In the present disclosure, the micro or nanofiber filter layers can bemanufactured by electrospinning and/or meltblowing techniques. Thesetechniques can be applied to the nanotube membrane and micro membranefilters, which use synthetic and natural polymers as their rawmaterials. Based on modern micro/nano technologies, the aforementionedfilters can significantly reduce the amount of particulate matters andtoxic substances inhaled.

In the embodiment shown in FIGS. 5A and 5B, the filter(s) can be used toreduce one of the gaseous components in the smoke, wherein the gaseouscomponents that can be reduced in the smoke include at least one ofcarbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde,acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine,nitrosamine, nitrogen oxide, benzene, NNN, phenol, catechol,benzoanthracene, benzopyrene, and any combination thereof.

Preferably, a material for preparing the filters or filter layers isfilled with a catalyst for decomposing, selectively, toxic matters. Forexample, CO generated by incomplete combustion of tobacco can beconverted into CO₂ by using a transition metal-manganese composite oxidecatalyst or a catalyst containing CuO, MgO. For another example,hydrogen cyanide can be catalytically decomposed into non-toxicsubstances by using silver nitrate and nickel nitrate nanoparticles orusing cobalt oxide or nickel oxide. Similarly, the level of phenol insmoke or aerosol can be reduced by using copper nitrate and cobaltnitrate. Nitrosamine can be catalytically decomposed by using one ormore rare earth oxides such as lanthanum oxide, cerium oxide andpraseodymium oxide.

More preferably, the catalysts included within one or more filters canbe activated or remain active under high-temperatures. Catalysts can beselected from a relatively wide range, for example, having an activationtemperature of between 600˜1000° C. Tobacco combustion can provide thedesired high temperature for catalyst activation.

Preferably, the materials used to make the filters and filter layers canselectively adsorb certain toxic gaseous components. When such filtersare placed in cigarette body and subsequently burned during smoking,some or most of the toxic matters adsorbed by the filters are subject tothermal decomposition. Selective adsorption can be combined with thecatalysts mentioned earlier to better facilitate the elimination ofharmful chemicals resulting from burning tobacco.

The present disclosure discloses a group of high efficiency filtermaterials which can be used for filtering for tobacco products,including electrospinning nanofibers, nanotubes, meltblown micrometernonwoven fabrics, spunlace nonwoven fabrics, cellulose acetate filterlayer, phenolic filter layer, synthetic polymer filter layer, activatedcarbon particles and the like, or combinations thereof. Electrospunnanofibers can be prepared using one or a mixture of synthetic polymersand natural polymers under normal temperature and pressure. Theelectrospun nanofibers can be sprayed directly onto the surface of themeltblown or spunlace nonwoven fabrics to form a composite adsorbentfilter, or they can be sprayed directly to tobacco or matters in thecigarette body portion, or sprayed directly onto or mixed with acetatefibers or other materials in the cigarette filter tip portion. Thematerials include synthetic polylactic acid, polyvinylpyrrolidone,nylon, poly Diols, polyvinyl alcohol, chlorinated polyvinyl chloride,diacetate, polyether sulfone, and natural polymers such as chitosan,silk protein, corn gluten, and combinations thereof. They can bedissolved in water, formic acid, glacial acetic acid, ethanol, isopropylalcohol in the concentration range of 10˜500 mg/ml,

For electrospinning, the concentration of the polymer solution can be 10to 500 mg/ml, and the solvent can be one or a mixture of the volatilesolvents. The number of syringes can be set to 1-2000 as needed, thenumber of electrospinning needles can be set to 1-2000 as needed. Thevoltage of electrospinning is the combination of positive voltage, whichis in the range of 0˜200 kV, and negative voltage, which is in the rangeof −0˜−200 kV. The total voltage difference is 10˜400 kV, the solutionmoving speed of each needle is 0.1-50 ml/hr, and the distance from thespinning needle to the receiving plate is 5-200 cm. The electrospinningprocess can also be carried out using a wire instead of the needles.

As described above, the filters described in the present disclosure maybe made by the process of electrospinning. The material(s) and theelectrospinning parameters used can be selected to provide filters likethose described above with the desired sizes and desired filteringcharacteristics. One or more catalysts can be added to the filters ifdesired. The filters can be located within a body of a tobacco productin the desired location during manufacturing of the tobacco product. Forexample, the body of the tobacco product may be considered as comprisinga plurality of segments, and the body can be filled with alternatingportions comprising primarily or consisting essentially of filter ortobacco. Alternatively, the body portion of a tobacco product may befilled with tobacco or one or more filters, then with one or morefilters or tobacco, respectively, and so on, such that the body portionof the tobacco product comprises alternating one or more tobaccoportions and one or more filter portions. In one embodiment, a filtermaterial can be electrospun onto a tobacco product to create a mixedcomposition of tobacco and filter materials, with the resulting mixedcomposition then placed into a body portion of a tobacco product, withthat body portion able to include one or more additional filters likethose shown and described herein if desired.

It should be noted that a tobacco product may include a plurality offilters, each adapted to provide certain desired filteringcharacteristics. As noted, two or more filters having differentporosities from one another can be placed in the body of the tobaccoproduct, thereby providing a size gradient for filtering particulates.In addition, two or more filters, each having one or more catalyststhereto, wherein the catalysts may differ from filter to filter, can belocated in the body of the tobacco product to thereby provide a varietyof filtering or adsorption characteristics as may be desired. Moreover,two or more filters, having the same or different shapes, the same ordifferent sizes, and/or comprising the same or different materials, maybe located within the body of the tobacco product to provide the desiredfiltering characteristics.

Although the present disclosure has been described with reference tospecific exemplary embodiments, it will be recognized that thedisclosure is not limited to the embodiments described, but can bepracticed with modification and alteration within the spirit and scopeof the appended claims. For example, although most of the foregoingdiscussion refers to cigarettes and to tobacco products, it should benoted, however, that the systems and methods of the present disclosurecan be used in a wider variety of products. For example, filters likethose described above may be included in cigars as well as cigarettes.Similarly, filters like those described above may be included in andpart of other smoking implements, such as pipes, hookahs, bongs, and thelike. Moreover, it should be noted that, although the foregoingdiscussion has focused on tobacco products and the smoking thereof, thefilters and methods described above may be used in connection with othersmoking products, such as pipe tobacco, marijuana, hashish, tobaccomixed with molasses or other sweeteners or flavors, other smokingmaterials for hookahs, and combinations thereof. Accordingly, thespecification and drawings are to be regarded in an illustrative senserather than a restrictive sense. Unless otherwise specifically stated,the terms and expressions have been used herein as terms of descriptionand not terms of limitation. There is no intention to use the terms orexpressions to exclude any equivalent of features shown and described orportions thereof and this disclosure should be defined in accordancewith the claims that follow.

What is claimed is:
 1. A tobacco product comprising: a body portion anda filter tip portion; tobacco within the body portion; wherein at leastone filter is located within the body portion.
 2. The tobacco product ofclaim 1, wherein the filter comprises a cone shape.
 3. The tobaccoproduct of claim 1, wherein the filter comprises a hemisphere shape. 4.The tobacco product of claim 1, wherein the filter comprises a foldingstructure.
 5. The tobacco product of claim 1, wherein the filtercomprises a disc shape.
 6. The tobacco product of claim 1, wherein thereare at least two layers in at least one filter, with the first layerlocated closer to a first end of the cigarette and the second layerlocated closer to the second end portion of the tobacco product.
 7. Thetobacco product of claim 6, wherein different layers in a filter havedifferent filtration or adsorption characteristics.
 8. The tobaccoproduct of claim 7, wherein the first layer is configured to block,adsorb, or disintegrate particles with larger sizes than the secondlayer.
 9. The tobacco product of claim 1, comprising at least twofilters in the body portion of a cigarette, with the first filter closerto a first end of the cigarette and the second filter closer to thesecond end of the cigarette.
 10. The tobacco product of claim 9, whereindifferent filters have different filtration or adsorption capabilities.11. The tobacco product of claim 1, wherein at least one filter in thebody portion is adapted to burn, or partially or completely disintegrateduring combustion of the tobacco.
 12. The tobacco product of claim 1,comprising a plurality of filters in the body portion and wherein thefilters are evenly spaced apart from each other within the body portion.13. The tobacco product of claim 1, comprising a plurality of filters inthe body portion and wherein the filters are unevenly spaced apart fromeach other within the body portion.
 14. The tobacco product of claim 1,wherein at least one filter is adapted to reduce at least one materialfrom the smoke or aerosol resulting from combustion of the tobacco. 15.The tobacco product of claim 1, wherein at least one filter isconfigured to reduce or remove from the smoke or aerosol resulting fromcombustion of the tobacco at least one of the following chemicals:carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde,acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine,nitrosamine, nitrogen oxide, benzene, NNN, phenol, catechol,benzoanthracene, and benzopyrene.
 16. The tobacco product of claim 15,wherein at least one filter comprises one or more catalysts adapted toreduce or remove one or more materials from the smoke or aerosolresulting from combustion of the tobacco.
 17. The tobacco product ofclaim 16, wherein the catalyst or catalysts is active or can beactivated at temperatures of between 600 and 900 degrees Celsius. 18.The tobacco product of claim 1, wherein at least one filter isconfigured to adsorb or block tar or particles resulting from combustionof the tobacco.
 19. A method of making a tobacco product, comprising:electrospinning non-toxic fibers; forming a filter comprising thefibers; locating the filter within a tubular body of a tobacco product;and locating tobacco within the remainder of the tubular body on atleast one side of the filter, wherein the fibers comprise micro-fibers,nano-fibers, or a combination thereof, and wherein the fibers areadapted to combust when the tobacco combusts.
 20. The method accordingto claim 19 further comprising the step of adding one or more catalyststo the filter.
 21. The method according to claim 19 further comprisingthe step of locating a second filter within the tubular body of thetobacco product and spaced apart from the filter, wherein tobacco islocated within the tubular body between the filter and the secondfilter.
 22. The method according to claim 19 wherein the tobacco productcomprises a cigarette.
 23. The method according to claim 20 wherein thefilter is adapted to reduce or remove at least one of carbon monoxide,ammonia, 1,3-butadiene, isoprene, acraldehyde, acrylonitrile, hydrogencyanide, 0-toluidine, 2-naphthylamine, nitrosamine, nitrogen oxide,benzene, N-Nitrosonornicotine, phenol, catechol, benzoanthracene, andbenzopyrene.
 24. The method according to 21 wherein the filter andsecond filter comprise fibers having different porosities from oneanother, thereby providing a filtering size gradient from one end of thetubular body to a second end, and wherein each of the filter and thesecond filter comprise a catalyst that is different from one another.